Virtually all pipe snubbing apparatus currently used to insert and remove pipe from oil wells or gas wells are hydraulically actuated. Some recent accidents with hydraulic snubbing apparatus have resulted in renewed interest in cable drawn pipe snubbing apparatus. In one recent accident, the hydraulic pipe snubbing apparatus failed without warning and well pressure propelled a length of pipe from the well with such force that it killed a rig worker who had the misfortune to be standing in the vicinity.
U.S. Pat. No. 1,894,912 (Otis 1933) is an example of a cable drawn pipe snubbing apparatus. However, the configuration of the Sage et al patent is not viewed as being suited to the present needs of the oil and gas industry.
U.S. Pat. No. 3,999,610 (Sage et al 1976) and U.S. Pat. No. 4,119,297 (Gunther 1978) use a combination of cables and hydraulics.